Bacteriology of the oral cavity of BALB/c mice

Abstract

To be used as a model in dental research, an animal must fulfil experimental needs and information on the composition and variation of its oral flora must be available. Only limited data are available on the indigenous oral bacterial flora of BALB/c mice. In this work, a total of 671 isolates from different sites (saliva, tongue, teeth, and mucosa) of the oral cavity of BALB/c mice were identified. Only 18 different species were isolated, which indicates the relative simplicity of the flora. The predominant species of the total cultivable flora were "Lactobacillus murinus" (38%), Staphylococcus aureus (37%), Streptococcus faecalis (8%), Staphylococcus sciuri (4%), and Escherichia coli (3%). The other species each represent less than 2% of the flora. "Lactobacillus murinus" is found in greater proportion on mucosa than in the other sites, Staph. aureus predominates in saliva, and Strep. faecalis was found in greater proportion in tooth samples. Statistical analyses, using the minimum percentage of similarity, indicate that there is some variation among the microflora of different mice but that this difference is smaller for mice from the same lot. These results set the basis for the study of the variations of the indigenous oral microflora of BALB/c mice under different conditions.

Comparison of the proportions of oral bacterial species in BALB/c mice from different suppliers

“…The discrepancies observed between these studies may be due to the different techniques used for the isolation and identification of the bacterial isolates and the statistical methods of evaluation. Our techniques were shown to recover 94-99% of the bacterial species present (Rodrigue et al 1989, Trudel et al 1986) and the appropriateness of the statistical methods that we used has already been discussed by Moore et al 1982Moore et al , 1984 The differences between the oral bacteria of BALB/c mice from the various suppliers could be attributed to: (1) significant differences in transit times and (2) the use of different diets by the suppliers (Taconic Farms: Agway NIH-31, Harlan Sprague Dawley: Teklad LM-485, Jackson Laboratory: Diet 911A (Emory), Hilltop Lab Animals: Prolab RMH-3000, Charles River Canada: Purina 5077). We showed previously that a modification of the sugar, starch or protein content of the diet could alter the proportions of the predominant oral bacterial species in BALB/c mice (Blais and Lavoie 1990).…”

“…The proportion of each oral bacterial species was determined by a colony-immunoblot technique (Rodrigue et al 1989, Rodrigue & Lavoie 1990. Bacterial isolates which did not react with any of our specific antisera prepared against the predominant oral bacterial species recovered from the BALB/c mouse from Charles River Canada (Gadbois et al 1993, Rodrigue et al 1989, Trudel et al 1986 were purified by subculturing twice and identified using API test strips (Staph Ident, 20 Strep, 20E, Rapid CHI (Biomerieux Canada, St. Laurent, Qc) (Gadbois et al 1993). The proportion~of the oral bacterial species were compared using the minimal percentage of similarity and the Lambda of Good (Lacroix' & Lavoie 1987, Moore et al 1982, Moore et al 1984 with the level of significance fixed at …”

“…In an exhaustive study of the oral cavity of BALB/c mice under aerobic and anaerobic conditions and analysing 671 strains of bacteria, we observed only 18 species. Lactobacillus murinus, Staphylococcus aureus, Enterococcus faecalis, Staphylococcus sciuri and Escherichia coli represented 90% of the total microbiota (Trudel et al 1986). Among diet components only sucrose, starch and protein content affected the relative proportions of the predominant oral bacterial species of BALB/c mice (Blais & Lavoie 1990).…”

“…Accepted 26 September 1995 In order to understand more fully the factors influencing the general bacterial ecology of the oral cavity, we developed a mouse model in which many factors have been studied already (Blais & Lavoie 1990, Deslauriers et al 1986, Gadbois et al 1993, Rodrigue et al 1993, Trudel et al 1986. In an exhaustive study of the oral cavity of BALB/c mice under aerobic and anaerobic conditions and analysing 671 strains of bacteria, we observed only 18 species.…”

Differential Recognition of Oral Indigenous Bacteria by Salivary Immunoglobulins A and G

“…These differences between individual immunoreactivities against quantitatively different components of the oral flora do not argue for a dose-dependence in the response to oral indigenous bacteria. It is possible, however, that some bacteria recovered at high frequency at oral sites (e.g., S. aureus) are not true residents of the oral ecosystem, being found predominantly in the saliva (28). It must be stressed, however, that Streptococcus sp., including faecalis, are predominantly recovered from oral surfaces (particularly from the teeth) and are likely to be permanent residents of the murine oral cavity.…”